During the past decade the role of Information and Communication Technologies (ICT) in education worldwide constitutes an ever more decisive factor in the evolution of the educational process and educational models. To this end, the use of Personal Computers (PCs) running proprietary software is the most common solution. At the same time an increasingly growing trend towards Free/Open Source Software (FOSS) adoption by companies of the private sector as well as public organisations and educational institutions around the world is resulting to proprietary software going open source. Although the prime motivation for deploying FOSS in educational settings seems to be the reduction of costs associated with licensing and ownership of commercial products, several other advantages that arise from FOSS deployment may be of even greater benefit. This paper examines the rationale for using FOSS in education, especially at school level and discusses the possible benefits and problems of this alternative. It also reviews the current state as well as the trends concerning the adoption of FOSS in schools and proposes ways to promote its use.